| Year | Total | vs prev |
|---|---|---|
| 2017 | 0 | −100.0% |
| 2016 | 160 | −94.2% |
| 2015 | 2,741 | +57.6% |
| 2014 | 1,739 | −7.2% |
| 2013 | 1,874 | −27.4% |
| 2012 | 2,580 | +7.2% |
| 2011 | 2,406 | +9.6% |
| 2010 | 2,195 | +826.2% |
| 2009 | 237 | — |
| 2007 | 0 | −100.0% |
| 2006 | 444 | −38.2% |
| 2005 | 718 | −40.6% |
| 2004 | 1,209 | −24.0% |
| 2003 | 1,590 | −21.8% |
| 2002 | 2,032 | −10.1% |
| 2001 | 2,261 | −0.3% |
| 2000 | 2,267 | +8.7% |
| 1999 | 2,085 | +8.1% |
| 1998 | 1,929 | — |